Stoker control



"Jan, 29, 1946.

w. w. HALLINAN STOKER CONTROL Filed April ll, 1942 5 Sheets-Sheet 1 Jan.29, 1946. w, W HALLINAN 2,393,680

l STOKER CONTROL Filed Apil ll, 1942 5 Sheets-Sheet 2,`

Jan. 29, 1946. w. w. HALLINAN sTofEn CONTROL Filed Ap'ril 121, 1942 5Sheets-Sheet 5 Jan. 29, 1946. w. w. HALLINAN 2,393,680

SgOKER CONTROL W. W. HALLINAN STOKER CONTROL Filed April lll, 1942 Jan.29, 1946.

5 sheets-sheetl 5 Patented Jan. 29, 1946 UNITED STATES PATENT OFFICEs'roKER CONTROL William W. Hallman, Menaota, nl.

Application April 11, 1942, Serial No. 438,627 14 claims. (o1. 11o- 101)The present invention relates to stoker controis, and is particularlyconcerned with improved systems and devices for controlling theoperation of coal stokers in such manner as to utilize the coal moreeiciently and to reduce temperature overrun to a minimum.

One of the objects of the invention is the provision of an improvedcontrolling unit for controlling and actuating the gears of the coalfeed and the supply of air for combustion, which is adapted to permitthe independent adjustment of the limits of operation of the airadjustment and coal feed adjustment, although both are actuated by thesame actuating device.

Another object of the invention is the provision. of an improvedcontrolling unit of the class desbribed. which is adapted to control thesupply of air for combustion and the-ratchet type'gear case for the coalfeed in such manner as to permit the provision of two definite rates ofcoal feed, one of which may be zero, and two denite rates of feed ofair, both of which may be separately and independently adjusted.

' Another object of the invention is the provision of an improvedcontrol system for stokers of the class described, in which the,controlling mechanism for changing the air and coal feed is driven fromthe same motor which drives the combustion blower and the coal feed,thereby eliminating the necessity for providing two separate motors oractuating devices.

Another object of the invention is the provision of an improved stokercontrolling unit of the class described, which is simple, sturdy,capable of being adjusted at any time, Whether operating or notoperating, and adapted to be used for a long period of time without anynecessity for repair.

Another object is the provision of an improved stoker controlling systemwhich is adapted to eliminate the use of deep fuel beds and to regulatethe coal feed and the air feed according to the steam pressure or bonnettemperature.r

Another object of the invention is the provision of an improved airconditioning and heating unit and controlling system which is adapted toeliminate the room temperature over-run above the thermostat settingthat is commonly present in the stoker fired units of the prior art,thus conserving fuel and raising the overall eciency of the heating unitto a maximum.

Another object of the invention is the provision of an improved heatingsystem which is adapted to operate at a high rate of fuel and air feedwhen low a predetermined value and which isalso' adapted, as soon as thesteam pres-sure or water temperature or bonnet temperature reaches suchthe bonnet `temperature or steam pressure is bevalue, to change the fuelfeed and air supply in such manner that air will continue to be suppliedIto burn up the excess fuel that has been forced into the fire pot onhigh feed, thus maintaining efficient combustion Without excessive coalfeed until the fuel previously supplied has been burned up and the rebed is reducedto a minimum depth, unless the steam pressure, watertemperthe stoker may be operated on low' coal and air feed at all timeswhen the outside temperatures are moderate and high coal and air feed isnot used at all until the outside temperature reaches a. predeterminedpoint, such as, for example 40 degrees F.

Another object of the invention is the provision of an improvedcontrolling unit for stokers of the class described which is capable ofbeing manufactured at a much lower cost by virtue ofthe elimination ofone of the motors of the type employed in my prior application, SerialNo. 422,400, led December 10, 1941, on Stoker controls, Patent No.2,354,517, issued July 25, 1944.

Another object of the invention is the provision of an improved airconditioning and heating unit and controlling system for it, by means ofwhich the fuel feed may be cut olf before the room thermostat issatisfied and the furnace operated at reduced combustion air supply, inorder to consume all of the fuel previously forced into the burner, thusreducing the fuel bed depth to a minimum at this time or just about the'time' when the thermostat will be satisfied for the purpose ofeliminating the regular. room temperature overrun above the thermostatsetting.

The solid fuel burners of the prior art with which I am familiar operatewith either a full fuel feed or a full air feed, or a combination ofboth, until 'the room thermostat is satisfied, thus causing an overrunof the thermostat setting and a stopping of the burner by the thermostatwhen there is a large fuel bed in the furnace.

This large fuel bed produces smoke and wastes the fuel at this timebecause the combustion air is also shut olf in the devices of thepriorfart, when the fuel feed is stopped. j

Another object of the invention is the provision of an improvedcontrolling system for stokers which so controls the combustion thatcoke trees are fully consumed when a coking fuel is used.

Another object of the invention is the provision of an improved stokercontrolling system in which, the same motor may be used for driving theair circulating blowers for the air which is discharged into the spaceto be heated and for the air of combustion and in which the supply ofairV for combustion isv not completely shut off, but may be merelyreduced so that whenever the motor is operating, the fuel bed in thefurnace is still provided with a reduced supply of air tc reduce smokingand to produce a more perfect combustion.

The present application is related to my prior application, Serial No.422,400, flled December 10, 1941, for Stoker controls, Patent No.2,354,517, issued July 25, 1944, in that the present applicationdiscloses a structure capable of vproducing the samev results, but forwhich it is only necessary to provide one electric motor. y

The present application is also related to my prio;` application,Serial'No. 346,763, filed July 22, 1940, for Combined air conditioningand heating unit, Patent No. 2,323,034, issued June 29, 1943. 1 l

Other objects and advantages of the invention will be apparent from thefollowing description and the accompanying drawings, in which similarcharacters of reference indicate similar parts throughout the severalviews. Y

Referring to the drawings: y

Fig. 1 is a diagrammatic elevational view of. the stoker controllingunit shown in connection with a wiring diagram embodying the presentimproved system of stoker control;

Fig. 2 is a vertical sectional view taken on the plane of the axis ofshaft 42. of Fig. 1, looking toward the left in the lower part of Fig.1, showing the details of construction of the control unit;

Fig. 3 is another vertical sectional view taken on the plane of the line3--3 of Fig. 2, showing the mode of drive of the coal feed and its con-Anection to the devices which are adapted to change over from low feed tohigh feed, or Vice versa;

Fig. 4 is a fragmentary sectional viewshowing the coal feed cam in twoof its positions;

Fig. 5 is another fragmentary sectional view, being an enlargement of apart of Fig. 2, showing the details of construction of the clutch whichpermits a positive actuating device to. move the coal feed and air feedlevers to high or low feed, although positive stops are also employedfor adjustment of the range of high and low coal, and air feed;

Fig. 6 is a fragmentary vertical sectional view taken on the plane ofthe axis of shaft 200 of Fig. 2, showing the electromagnet supportingframe in two of its alternative positions;

Fig. '7 is a similar fragmentary end view of the same frame in one ofits positions;v

Fig. 8 is atop plan view of the control unit, with the coal and air feedlevers broken off;

Fig. 9 is a vertical sectional view taken on the plane of the line 9--9of Fig. 2, showing details of construction of the electromagnet which isused to control coal and air feed;

Fig. 10r is a fragmentary sectional view taken on the plane of the lineIIJ-I0 of Fig. 2,A looking in the direction of the arrows; Y

Fig. 11 is a sectional view taken on the plane of the line II-II of Fig.5, looking in the direction of the arrows;

Fig. 12 is a fragmentary sectional view taken on the plane of the lineI2-I2 of Fig. 5, looking in the direction of the arrows;

Fig. 13 is a fragmentary sectional view taken on the plane of the lineI3-I3 of Fig, 5, looking in. the direction of the arrows;

Fig. 14 is a sectional view taken on the line Il-,M Aof 5,.V lookinginthe direction of the arrows;

Fig. 15 is a fragmentary sectional view, taken through one of theadjustable stops for controlling ythe range of coal feed;

Fig. 16 is a wiring diagram of a modified circuit for a controllingsystem in which the coal feed is also controlled responsive to theoutside temperature, that is, the temperature outside of the house beingheated.

The present controlling devices and controlling system are adapted to beused in connection with the combined air conditioning and heating unitdisclosed in my prior application, Ser. N o. 346,763, led July 22, 1940,Patent No. 2,323,034, issued June 29, 1943; and the present controls maybe substituted for those which are disclosed in that application.

In some embodiments of the invention the same driving motor may also beused for driving the blower which circulates the air through the bonnetof the furnace and for driving a pump which may circulate the water in ahot. water system.

In the embodiment which has been selected to illustrate the inventionthe latter actuating devices have been omitted, and the motor isdisclosed as actuating the blower for supplying the air of combustionand driving the gears which actuate the coal feed.

Referring, to Fig. l, this is a diagrammatic View showing` the improvedcontrolling unit for the Stoker in connection with a wiring diagram. Inthis gure the driving motor is indicated by the numeral I0, and itsshaft I I may project from both ends for purpose of driving a blower orimpeller carried in a blower housingv at one end and for driving thecoal feed from the other end of the shaft.

For this purpose the shaft I'I carries a V pulley I3 at its right end,which drives .a pulley I4 by means of a V .belt I5, the pulley I4 beingmounted on a driven shaft I6 extending into the gear housing Il.

The gear housing I'I contains any standard form of speed reduction gearsconnecting the shaft I6 with the driving feed' screw of the screwconveyor in the conveyor tube of the Stoker.

The speed of operation of the feed screw is determined by theposition ofthe shaft I9, which has the usual adjustments, as indicated, forpermitting the drive of the screw at a number of different speeds fromzero, indicating no drive, to speedNo. 4.

This. mechanism may be so adjusted that the controlling system can drivethe screw at high feed or low feed, and the rate of speed is controlledby the angular position of the shaft I9.

The gear boxr I1 is provided, with the indicia 0, I, 2, 3, and 4, merelybecause it is the same gear box utilized in my prior application. Thepositions and stops of the coal feed are, however, located and indicatedby the controlling unit |00, of which the face plate 31 forms a part.A IThe shaft I9 is adapted to be actuated by the crank arm 20, which ispivotally connected to a connecting rod 22, and the connecting rod 22preferably consists of two strips of sheet metal 22a and 22h joinedtogether by means of a pair of screw bolts 22e which are threaded intothe lever 22h and which pass through the slot v22d in the lever 22a.

As the control unit is located somewhat in advance of the gear box |1,there is an oifset in the lever 22h at 22e so as to bring the crank arm20 into a plane located just outside the gear box 1.

The connecting rod 22 is pivotally connected at its left end by means ofa rivet |38 to a coal feed lever |21, further to be described. l

The blower housing I2 may have its inlet located at 2S, surrounding theshaft and the inlet 26 may be connected to a pipe 21, open at its lowerend 2B, but adapted to be controlled by a butterfly air valve 29, Thebutterfly valve 29 is carried by a shaft 30, having a crank arm 3|located outside the pipe 21, and the crank arm 3| is pivotally connectedat 32 to a connecting rod 33, comprising two sections slotted andsecured together by bolts 34 so that the connecting rod is of adjustablelength.

The connecting rod 33 has its opposite end pivotally connected by meansof a rivet 35 to an air supply lever |26 (Fig. 10, further to bedescribed), also actuated and controlled by the motor I0.

i In the present controlling unit the air and coal feed adjustments arecontrolled by means of an electromagnet |15, which is not visible inFig. 1'

mined high feed and a predetermined low feed,`

and for complete cut-off of the coal feed,

` The present controlling arrangements are adapted to be used not onlyfor the air conditioning and heating units shown in my priorapplication, above mentioned, but also for stokers which are installedin old furnaces, or boilers.

When these controlling arrangements are used in old furnaces, the coalfeed would not be completely cut off, but would be merely reduced fromhigh feed to low feed, such as a No. 1 feed on low.

In other embodiments of the invention the coal feed may be completelycut off when the air feed is cut to a minimum. This may be accomplishedby setting the lower range of movement of the coal feed controllinglever at zero, a zero coal feed indicating zero speed of the oper-atingscrew, or no feed at all.

The electromagnet is an A. C. magnet It is adapted when energized tohold the coal and air feed on low, which, as described above, may beeither a zero coal feed or a No. 1, or other setting; but, as to airfeed, there is always some air feed when the motor is operating.

The air feed continues, at least in some measure, whenever the motor isoperating, because the blower is directly connected to the motor, andthe butterfly valve 29 does not completely shut olf the intake to theblower.

Referring to Fig. 2, the details of construction of the controlling unit|00 and its relation to the driving mechanism of the stoker, which is included in the housing |1, are there shown in greater detail.

The shaft'IS is drivenby the motor I0 at a substantially continuousspeed when the motor |0 is energized, and itis provided with a drivingworm or screw 40, which meshes with a worm gear 4| 'rotatably mountedupon the shaft 42.

The housing |1 has its rear wall 43 provided with a bore 44 forreceiving the bearing 45 and with a counterbore 46 for receiving theball bearing unit 41.

The housing |1 has a pair of forwardly projecting side walls 48, 49 andthe top and bottom walls 50, 5|, and is provided with a pair ofelongated foot flanges 52, 53 (Fig. 1). The forward side of the housingI1 has a. front wall 54, having a circular aperture 55 in it, which isclosed by a cover plate 56, secured in place by suitable screw boltswith a, gasket 51 interposed between ground surfaces so that the housingmay he filled with semi-solid lubricant.

The worm gear 4| is provided with a cylindrical hub portion 58 (Figs. 2and 3) and with a cylindrical but eccentrically located cam 59 carriedby the hub 58. A ratchet wheel 60 (Fig. 2 and Fig. 3), provided withteeth 6|, has an elongated cylindrical hub 62 for receiving the shaft42, 63 indicates the bore of hub B2.

The hub 62 is rotatably mounted in a bearing bushing 64 carried in acylindrical bore 65 in the cover plate 5G. The hub 92 projects from thebearing 64 with the shaft 42, and the hub 62 is secured to the shaft bya. through pin 66a. having a drive fit in the bores 66, 61, 68. This pinmay be slightly tapered, and it secures the ratchet wheel 60 to theshaft 42.

The shaft 42, is the shaft which drives the coal feed mechanism, such asa feed screw (not` shown). For example a, gear or driving pulley for thefeed screw may be mounted on the right end of shaft 42 in Fig. 2. Thisshaft is driven only through the intermediary of the ratchet wheel 60,since the worm gear 4| rotates freely upon the shaft 42. The cover plate56 supports at its lower side a stub shaft 69, the knurled end 10 ofwhich has a frictional fit in a cylindrical bore 1i of the cover plate56.

The stub shaft B9 is adapted to support for pivotal movement anoscillating lever 12, which is actuated by the cam 59. The oscillatinglever 12 may comprise a relatively wide metal member having a camaperture 13 for receiving the off center cylindrical cam 59.

The cam aperture 13 has the two oppositely disposed straight-,sides 14,15, and these straight sides are spaced by an amount equal to thediameter of the cylindrical cam 59.`

The partially cylindrical end walls 16, 11 of the cam aperture 13 maytake any desirable shape, but they are spaced from each othersufficiently to provide a clearance between these end walls and thecylindrical cam 59, as this cam rotates eccentrically on the shaft 42.

Thus the spacing between walls 16 and 11 must at least equal twice theradial distance from the center of the shaft 42 to the outside of the icam 59 at that point where the cam surface is ries a smb shaft 119,which has a pressed nt in a cylindrical bore 80 in the lever 12- Thestub shaft 19 projects toward the left in Fig. 2 and has a pivotal nt inthe cylindrical bore 8| of a pawl 82. A cotter pin 83 retains the pawlon the shaft. The pawl 82 is shown in Fig. 3, and it comprises a leverhaving a lbore 8| at one end and having a chisel-like tooth 84 extendinglaterally downward from. the other end.

The tooth 84 has a radially extending end shoulder 85 and a beveledcamming shoulder 88., The teeth 6| of the ratchet wheel have a. radiallyextending shoulder 81 opposing the end shoulder 85 of the pawl 82 andabeveled camming shoulder 88 which lifts the pawl 82 against the forceof gravity when the pawl 82 is drawn toward, the left over the ratchetwheel 80t The maximum range of movement of the oscillating lever i2 isshown in the dotted line position in Fig. 4, as'compared with the fullline position in that figure; and during this maxlmum range of movementthe pawl 82 may traverse a space on the periphery ofi the ratchet wheel60 equivalent to four teeth when there are fourpositions of coal feedadjustment, excluding the zero feed.

The bearing bushing 84 has a radially extending ilange 90 provided witha cylindrical surface 9|, which is rotatably received in a complementaryaperture in a cam dise' 92. They cam disc S2' is shown in Fig. 3, and ithas a partially cylindrical outer surface 93, which is suitably locatedso that it will pass under thetooth 84 of the pawl 82 and control thedropping of that tooth into the tooth spaces of the ratchet wheel 60.Thus the cylindrical surface 93'r is at a radius equal to or slightlylarger than the outer radius ofthe teeth 6| on the ratchet wheel 60, andthe length of this cylindrical surface 93 on. the periphery of the cam92' is sufficient to cover four teeth in the embodiment illustrated,which has four' coal feed adjustments.

ln addition to the peripheral surface 93, the coai feed adjustment cam92 has another toothed portion provided with teeth 95 for engaging theteeth S6 on a gear segment or partially toothed. disc 9T. Onlysuiiicient gear teeth 95 and 96 need be provided on the members 92 and91 to permit the rotative movementl of the feed. adjustment cam 92' tothe extent described hereinafter.v

The gear segment 91 is flxedly secured to a shaft 98, which is rotatablymounted. in the front tl of the housing, and which carries on its outerend the hub |9 of lever' 20 (Fig. 1), previously described.

This hub |94 is provided with a pointer 99, which indicates the coalfeed adjustment with respect to the numerals 0 to ll,v inclusive', onthe housing, but this indicia may be eliminated, since suitable indiciais now provided on the cone trolling unit I 00.

The operation of the coal feed adjustment, just described, is asfollows:` When the lever 20 is arranged in the position shown in Fig. 1at 0 coal feed adjustment, the gear segment 91 has rotated the coal feedadjustment cam 92 to such a position that it masks or covers all of thefour tooth spaces of the ratchet wheell |50v into which. the` tooth 84of pawl 82 could otherwise drop by gravity.

As a result of the interposition of the cylindrcal surface 93 betweenthe tooth spacesv of the ratchet wheel. 80 and the pawl 82,` the pawl 82merely slides back and forth on the surface 93', as the motor I0trotates the shaft I6 continuously,

and the cam 59 oscillates the lever 12 with its pawl 82. i

When the coal feed adjustment lever 20 is moved until its pointer pointsto this rotates the shaft 98 and the gear segment 91; by means of teethand teeth 96 the coal feed adjustment cam 93 is moved clockwise in Fig.3 to such a position that one tooth space of the ratchet Wheel 60 isexposed for receiving the paw] 82.

The members 20, 98, 91, and 93 are then held in xed position or xedadjustment, while the lever 12 oscillates as described before, throughthe same range of movement, carrying the pawl 82 with it. Duringthree-fourths of its movement the pawl 82 slides on a cylindricalsurface 93 and cannot drop into the teeth below it, but at the lastportion of its movement toward the left (Fig. 3), pawl 82 is thenpermitted to drop into one of the tooth spaces of the ratchet wheel 60.

During this remaining one-quarter of its movement. the pawl 82 has itsshoulder 85 engaging the shoulder 81 of one of the teeth 6| on theratchet wheel 60, and it moves the coal feed ratchetr peripherallythrough a distance of one tooth.

The shaft l2 is the one which drives the coal feed screw or other coal.feeding mechanism, and thus when the coal feed adjustment is at No. l,there is a minimum coal fed, step by step, equal to the amount which isbrought about by rotation of the coal feed ratchet, a distance of onetooth for each oscillation of the lever 12,y or for each rotation of thegear 4 This is the slowest rate of coal feed, the zero coal feedcorresponding to no movement of the coal feed.

In a similar way the coal feed adjustment may be made such that twoteeth are engaged by the pawl in its oscillating movement, or threeteeth, or four teeth.

The four toothed engagement of the pawl corresponds to' amaximum coalfeed.

It will thus be observed that the coal feed may be adjusted while thedevice is operating by merely rotating the lever 20, which in turn isactuated by the lever 22.

The stub shaft 19 has been provided. with a cylindrical extension i0(Fig. 2) which isl pivotally connected atone end to a link |02. The link|02 carries at its other end a stub shaft |03, to which it is pivotallyconnected; and the stub shaft |03 is xedly secured to the crank arm |04.The crank arm |04 is flxedly secured to the stub shaft |05, which isrotatably mounted in a bearing bushing |-06a, carriedv by the upperfront 54' of the housing l1.

The purpose of. this mechanism. just described is to take' oli powerfromv the gear housing of the coal feed, to actuate the controllingunil'l |00 without the necessity for employing another motor.

As the stub shaft 19 is carried by the oscillating' lever 12, itoscillates throughoutan arc and moves the link |02' back and forthV andwith it the crank lever |04- is caused to oscillate, oscillating theshaft |05.

The control unit |00 may be carried by the motor mounting plate |06,which is located on topof the gear housing I1 and below the motor |0, towhich part it is secured by suitable screw bolts. The entire controlunit is carried by plate |06,. through the intermediary of a face plate|01', which has its upper attaching flange |08 `accanto secured to themotor supporting plate vby screw bolts |09. Y

The face plate |01 is provided with a centrally located aperture H0forpassing the end of a stub shaft |I|. The stub shaft is carried by asupporting plate H2 (Fig. 5), which has' an aperture H3 for passing thereduced threaded end of the stub shaft for receiving a nut I4, whichclamps the stub shaft to the plate H2.

Plate H2 is xedly secured to the back of the face plate |01 by a pair ofscrew bolts ||5 (Fig 1), which pass through plate I 01 and are threadedinto plate H2. The face plate |01 is provided with a generally arcuateaperture H6, (Fig. 1) which is located on an arc determined by a radiustaken from the center of the shaft I H.

The arcuate aperture H6 does not have cylindrical walls, but has whatappear to be scalloped walls, but which, in fact, are a plurality'ofcylindrical grooves formed in each of its side walls opposite to eachother in such manner as to define portions of a socketgfor receiving thecylindrical portion I I1 of a button I I8.

Seven such4 partially dened sockets are provided in the arcuate apertureI6, two'being occupied by the stop members I I8 and I I 9 in Fig. 1,those unoccupied being indicated by the numerals I), I, 2, 3, and 4, ininverse order; i

The structure of these stop members H8, H9

is illustrated Vin Fig. 15, where the stop member` H8 is shown. Thisstop member H8, as previously stated, has a cylindrical portion HI.` Italso has a head |20a with a cylindrical knurled surface.

The stop member H 9 has a cylindricalbore |2|c passing axially throughit and adapted to slidably receive the cylindrical shank I22a of anelongated rivet |23a. The rivet I 23a passes through an arcuate aperture|2401, which is formed on concentric curves, `having as their center theaxis of the shaft III.

The arcuate aperture |24a guides the shank IEE-d of the rivet |23a asthe stop is being shifted, and the rivet |23'a`has its head I 25aengaging behind the plate H2. The stop member H8 has a largercounterbore |26a at its outer end Yto vprovide an annular shoulder |2'1afor engaging one end of a helical compression spring I28a. The otherendof the helical spring engages the inner face of a washer |29a, whichfits on the reducedcylindrical end |30a of the shank |22a4 and issecured by the riveted portion I3 Ia.

The spring |2811 constantly urges the stopI member I Steward the head|25a ofthe rivet I23a and holds the stop member in any one of the sevensockets previously described and shown in the face plate |01 in Fig. 1.

Thus the stop members I I8, I I 9 may be located at any of the positionsindicated in Fig. 1, or the two end positions, which have no indicia.These stop members define the range of coal feed, adjustment, and thecoal feed adjustment may be held at zero or may be extended between thestop members I I8, H9, in any of the positions shown.

As the normal operation of the device contemplates a low and a high coalfeed adjustment, the stop members I I8, I I9 will usually be. fartherthan one space apart; but it is possible to adjust the device so that itwill be constantly kept on high coal feed or low coal feed or inintermediate feed.

The face plate preferably has the words vCoal VFeed Adjustmen on it,above the "arcuate: slot I IB; and it also has stop members I I8, H9to'disnecting rod 22.

tinguish it from the air adjustment, which is at the bottom of the unit|00.

The stub shaft (Fig. 5) preferably has an enlarged cylindrical shank|20, and it is clamped in place by the hut H4, which draws the annularshoulder I 2| against the back of the plate H2. At its opposite end thestub shaft has a head |22, and it rotatably supports a rectangular block|23, having a centrally located cylindrical aperture |24.

The block |23 preferably has its corners cut off and slightly rounded,as indicated at |25 (Fig. 12), and it rotatably supports a plurality ofmetal plates |26, |21, |23, each of which has a cylindrical aperture,all of the apertures being indicated by the same numeral, |29. Theaperture is of a suitable diameter so that the plates are rotatablymounted on the rounded corner portions |25 of the metal block |23.

There are a plurality of ber washers made of suitable material, such asindurated fiber, carried by the rectangular block |23, and the fiberwashers are indicated by the numerals |30, |3|, |32, and |33. Thesewashers |30|33 may be circular in shape, and they are provided with acentrally'located squared aperture, all of these apertures beingindicated by the numeral |34 so that the washers t on the rectangularblock |23 and rotate with it, whereas the plates rotate on therectangular block, but are engaged by the washers in the manner of afriction clutch.

The washer |33 is thicker than the Washers I 30-I 32, and it is providedwith a cylindrical aperture |33a, which receives the cylindrical shank|20 of the stub shaft I II, in addition to a slot |35 for receiving Yatransverse pin |36, which passes through an aperture in the shaft. Pin|35 is positioned in an aperture in the shank |20 and is located in theslot |35 in the washer |33 to hold this Washer against rotation andfixed with respect to the shaft.

Thus the end washer |33 is keyed to the shaft by means of the pin |36 sothat this washer does not rotate with the block |23. It differs in thisaction from the washers |30|32 because, while they are xedly secured onthe block |23, vthey may rotate with the block on the shaft HI.

A spring washer |31 is interposed between the head |22 and the rear faceof washer |33 so that all of the plates andl ber washers are placedunder a predetermined resilient compression and kept in engagement witheach other.

The plate |21 comprises a rectangular steel plate, the longest dimensionof which may be two or three times its width. 'I'he plate |21, aspreviously described, is pivotally secured by means of astud |38 rivetedin the plate to a con- The plate |21 may also be called a coal feedlever, and at a point suitably spaced from the center of the shaft |I|the plate |21 is provided with a stop member |39.

This stop member may consist of a strip of metal bent at right angles sothat one portion may form an attaching flange welded to lever |21, andthe other portionl projects forwardly through the slot I I6 in the faceplate in position to engage the stops H8, H9.

The relation of the coal feed lever |2'I and its connection to theconnecting rod 22 and the crank 29 are such that when the stop member|39 is located underneathone of the indicia, the; crank 20 of the gearbox is in a corresponding of steel, which is pivotally secured by'xneansof a rivet 35 to the connecting rod 3-3, which controls the butterflyair valve `29.

'In this case the lower end of the air feed lever |26 has a projectingear, which is bent at right angles, and indicated at |4| (Fig. 2). Thisear forms a stop member, which projects through the arcuate slot |42 inthe face plate in position to be engaged by the stop members |43, |44.

The words Air adjustment appear on the face plate above the slot |42.Ii' desired, suitable indici-a may also be included to show the degreeof opening of the butterfly valve 29.

The stop members |43 and |44 may be identical in construction. They areslidably mounted in a slot |45, located in the backwardly turned flange|46 on the lower end of the face plate |31.

The slot |45 extends over almost the full width of the face plate sothat the arcuate slot |42 may be utilized to its fullest amount. The twostop members |43, |44 are similar in construction, and each comprises aknurled cylindrical thumb screw |41, having a smaller cylindricalthreaded screw bolt |48.

The screw bolt |48 passes through the slot |45, in each case, and isthreaded into the horizontal ange |49 of the stop member |43 or |44, asthe case may be. The upwardly extending flange |50 of each stop memberis long enough to .extend into the path of the stop |4| carried by theair feed lever. Thus the stop members |.4:3, |44 are adapted to definelimits of movement of the air feed lever and to determine to what degreethe air conduit 21 shall be shut oi and to what degree it shall beopened at its maximum opening.

The face plate |01 is preferably kDrovisled with a supporting frame forthe controlling mechanism, which may comprise a substantiallyrectangular strip of sheet steel |51 (Fig. 8) having its front end |52bent to .form an attaching flange. which is secured to the ,face plateby a plurality of screw bolts |53..

At its rear end the frame plate is bent at right angles and providedwith a laterally extending portion, which has an aperture |55, Servingas a bearing for a stub shaft |56. l

The controlling mechanism for the unit is preferably mounted in a frameor housing |51,

which may take the ,form of an upwardly open box of sheet metal. The boxor housing |51 has end walls |28, |59, and side walls |60, |6|; and theend walls are used for its pivotal support on the controlling unit.

Thus the end wall |59 has an aperture |62 for receiving the stud bolt|56. The head of the yStud bolt engages the inner side of the end wall|59, and .a cotter pin |63 may pass through the stud bolt to act as athrust bearing at its other end. The stud bolt |56 also preferablypivotally supports an actuating lever |64, which preferably comprises arelatively thick bar of steel or other suitable metal, having anaperture for receiving the stud bolt |56.

The lactuating lever |64 has an engaging member |65 secured to its upperend, and this engaging member may J,consist `of a forwardly extendingflange |66` and a depending flange |61..

The actuating lever |64 is so .connected to the driving mechanism in thegear housing that it is constantly oscillated back and forth .on itspivotal support, that is, the stud bolt and it .is adapted to move thecontrolling mechanism under certain conditions lwhen the engaging member1611s in a predetermined position.

The connection between thoaotuatlug .lever |64 and the mechanism in thegear housing may consist of a shaft |05, which projects from the gearhousing, being rotatably mounted in .the bearing |8611 in Fig. 2.Flxedly secured to the end .of the shaft |05 there is a lever |68, whichmay be secured tothe ,shalt by c set screw 69.

The lever |68 is plvotally connected to a pair of connecting links |10by means of another stub shaft |1|, having a head and a cotter pin. Thepair of connecting links |10 are pivotally congxected to the actuatinglever |64 (Fig. 2) by a stub shaft llla, having s, cotter pin at eachend. In other words, the depending end of lever |68 is pivotallyconnected to a link |10, which is pvota'lly connected to the lever |64by stub shaft |1|.

The end wall |28 corresponds to the metal plate |26, previouslydescribed, and has a square opening for engaging the block |23. Thus thecomplete housing |51 is pivotally supported on this end by means of theend wall |28 and the block |23, since the block |23 is fixed on stubshaft I.

0f course, the stub shafts and |56 are coaxial. Located in the housing|51 there is an electromagnet |15 consisting of a soft iron core |16,carrying suitable insulated winding coils |11. The core |16 passesthrough the coils |11 and is carried by a soft metal bracket |18, whichforms a continuation of the magnetic circuit. The bracket |18 has avertical flange, which is xedly secured to a supporting spider |19 (Fig.8) which in turn is carried by the upwardly extending flange of a.supporting bracket |8|. |18a 1ndicates a sheet of flber board insulationinterposed between the spider |18 and the bracket |18.

The .supporting bracket |8| is flxedly secured to the bottom of thehousing by bolts and nuts |82. The magnet |15 is preierably arranged forenergization by alternating current: and there- .fore it 'has its coreor noie piece I 16 Split, and half oi? the pole piece is surrounded by acopper ring |83 (Fig. 9), which causes such a lag .in the changing fluxthat the armature is constantly 'held when the windings are energized,irrespective of the changing intensity o f energization.

The electromagnet |15 has an armature |84, comprising a member of softiron. having a depending portion adapted Ito be attracted to the polepiece |16, The armature |34 is movably Illolmtd .0h the bracket |18,which comprises part .of the magnetic circuit, as follows:

bracket |18 has a rearwardly extending flange |85, which terminates in apair of narrow ears |86 (Fig, 8), one of which is at each side of theflange |85. The armature has a vertical ilange |81 and a. horizontalflange |88. The vertical fiange has a slot |89 at each side forreceiving each ear |86.

The slots and ears have suitable clearance to permit a limited pivotalmovement, The ears |86 have inwardly projecting lugs |90, which engageoutside oiA a spring plate 19|, which itself a slot at each endforreceiving the ears |86. spring plate .19| may be bowed forwardly.from its ends to engage the vertical flange of the .armature and holdit on the flange The horizontally extending ange |38 of the armaturecomprises a narrow strip which engages a vertically extending stud orstop membei |82 (Fig. 2) carried by the core frame |85 to limit themovement of the armature flange |81, away from the pole pie'ce |16.

The stud 92 also carries one end of the closed loop of a. helical spring|93, the other end of which is hooked about an upwardly projecting |95in the armature |84. The spring |93`urges the armature into a positionaway from the pole piece |16 with the flange |88 engaging stop |92.

The lower end of the armature may have riveted to it a connecting pin|96 (Fig. 2), which serves as a connecting member for connecting thearmature to a controlling plate, indicated in its entirety by thenumeral |91.

'I'his controlling plate may consist of a piece of sheet metal, whichhas bearing ears |98, |99.

turned at right angles adjacent its lower side.

ear |94 8), which is located in an aperture engages a spiral spring 203,the other end of which engages the controlling plate |91. Any suitablenumber of washers may be interposed between the spring 293 and thecontrolling plate |91 or between the contro-lling plate |51? and thearmature flange |81 so that the controlling plate is properly locatedlto accomplish its purpose when the armature is in released position andin contracted position.

The controlling plate in elevation is substantially rectangular inshape, but is formed with a slot 204 extending into its upper edgemidway between the sides. The upper flanges 265, 206 on each side of theslot 204 are in different planes.

This may be accomplished by making the controlling .plate of a pluralityof plates Welded t0- gether, as shown in Fig. 8, or the upwardly eX-tending flanges 205, 206 may be bent so as to be offset from each otherinto different planes. 'Ihe width of the slot 294 is sufiicient to passthe depending flange 61 of the contacting member |65. That is, the slotis wider in a horizontal direction than this flange |65.

The anges 205 and 206 (Fig. 8) are offset into different planes onlysuiciently in relation to the thickness of the contacting flange |61 sothat as the contacting flange |61 oscillates back and forth it mustengage one or the other of the upwardly extending flanges 205 or 206. Inthe contracted position of the armature the flange 296 is in the path ofthe oscillating lever |65.

In the released position of the armature the upwardly extending flange205 is in the path of the contacting member |61 on the oscillating lever|64. The spring andpin connection |96y 203 between the armature and thecontrolling plate |91 is for the purpose f eliminating chatl a source ofpower is taken off this gear box by means of the projecting shaft |95so' that the crank arm |68 and the connecting links |19 cause theactuating lever |64 to oscillate back and forth through a predeterminedarc at all times when the motor is operating.

'I'he purpose of the controlling unit is to utilize this motion andcontrol it electrically so that it may be used to move the coal feedadjustment to high or low and the air feed adjustment 'to high or low,irrespective of the range of adjustment.

When the armature is released, the control plate |91 moves away from thearmature to such a position that the part |61 carried by the oscillatinglever |64 strikes the upwardly extending flange 205, which is in theplane nearest to the electro-magnet.

Then the oscillating lever |64 clears the flange 296V in its oscillatingmovement, but engages the flange 295; and as a natural result theoscillating lever pushes the ange 205 of the control plate in acounterclockwise direction in such manner as to pivot the entire box |51on its stub shafts and |56 to a maximum counterclockwise position.Thereafter the vlever |64 continues to oscillate as long as the motor isenergized and the gears are rotating in the coal feed box; but as longas the armature is deenergized the oscillating lever |64 causes nofurther movement of the control plate |91 because the only flange 205which it could engage has already been moved counterclockwise beyond therange of movement of the oscillating lever |64.

In a similar way, when the armature is energized, the control plate |91is pivoted counterclockwise in Fig. 2 toward the electromagnet. Theflange 205 is moved out of the plane of movement of the flange |61 onoscillating lever |64, but the flange 206 is moved into the plane ofmovement of the flange |61 on the oscillating lever |64.

On the next movement of the Oscillating lever |64 in a clockwisedirection, looking at it from the front, the lever |64 will have itscontacting member |65 engage the flange 206 of the control plate |91.This will pivot the entire box in a clockwise direction to its positionof maximum clockwise movement.

Thus the driving mechanism is adapted to move the housing |51 to eitherof two positions, which may correspond to maximum coal and air feed andminimum coal and air feed.

The movement of the housing 51 into these maximum positions does notnecessarily mean that the coal feed and air feed levers are moved to thesame extent. The housing Wall |28 is frictionally engaged between thefiber plates or discs |32, |33.

Therefore, whenever the housing rotates it tends to move both of thesediscs. The disc |33 is keyed to the stub shaft with which it moves; butthe disc |32 .tends to move with the end wall |28 of the housing, withthe following results.

The disc |32 tends to rotate the plate |21 with it, which engages thedisc 3|, which tends to rotate the plate |26 with it. These coal and airfeed levers |21 and |26 have their range of movement determined by thestops 8, ||9, and |43, |44, respectively,

Since the coal feed and the air feed levers are driven through theintermediary of friction discs like a clutch, these feed levers aremoved until they engage the stops ||8, ||9 or |43, |44; and then theystop, each being independently controlled by its stop members.

Whenever a coalfeed or air feed lever stops at any position, it does nothinder the housing |51 from moving onward to its maximumcounterclockwise or clockwise position.

Thus the coal and air feed are moved to any adjusted maximum coal andair feed when the electromagnet is de-energized, and kept in thatposition as long as the magnet is de-energized. When the magnet isenergized, the coal and air feed are moved to the adjusted minimum coaland air feed, and kept there as long as the magnet is energized.

Referring now to Fig. l, this diagram also includes a circuit diagramfor controlling the electric motor l0, which drives the coal feed andthe electromagnet |15.

The present circuit is adapted to be energized by ordinary 110 volt 60cycle A. C. lighting circuit 2|6, and numerals 2|0, 2|| indicate thesupply conductors for energizing the present circuit. A

double pole disconnect switch is shown at 2|2, interrupting theconductors 2|0, 2||.

The conductor 2|| is connected to one of the contact arms 2 I3 of alimit switch 2|4, which may consist of any thermostatically actuatedswitch located, for example, in the bonnet of the furnace. The othercontact of the limit switch is indicated by numeral 2|5. ZIB indicatesin its entirety an operating switch which comprises a thermostaticswitch member having ya pair of contacts 2|1, 2|8,

These may be thermostatic switches arranged in the same housing andlocated to be actuated from heat derived from the temperature of the airin the bonnet of the furnace or adapted to be actuated at apredetermined steam pressure in the boiler by means of a pressureresponsive bellows located in the boiler or having a bulb in the boiler.

In hot water systems these may be thermostatically actuated switches2|"4, 2| 6, which are actuated responsive to the temperature of thewater in the boiler.

The'operating switch 2 I 6 is arranged so that it closes on high bonnettemperature, and the limit switch 2|4 is so arranged that it opens onhigh temperature. The other contact 2|5 of limit switch 2|4 is connectedby conductor 2|9 to one terminal of the primary 22|] of a step-downtransformer 22|.

The other terminal of the primary 220 is connected by conductor 222 toconductor 2|0, which is the other side of the line. Thus the limitswitch is arranged to operate at 110 volt energization, and to open theentire energizing circuit when the temperature reaches a predeterminedlimit.

The transformer 22| has a secondary 223, which provides current at alower potential for control of relays and the like, and one terminal ofthe secondary 223 is connected by conductor 224 to the coils of a relay225. The other end of the coils of the relay 225 is connected byconductor 226 to a conductor 221.

The time switch is indicated in its entirety at 228, one contact 229being connected to conductor 221, and the other contact 230 beingconnected to conductor 23 I, which leads to the other terminal of thesecondary 223, This time switch 228 is controlled by a synchronous clock238. Thus the time switch 228 controls the relay 225.

A synchronous electric clock motor 238 is indicated in the upper part ofthe circuit by a circle and by the numeral 238, and it has its terminalsconnected tc two conductors 232, 233. The motor 238 is a 110 volt A. C.motor, and conductor 232 is connected to one side of the line by beingconnected to the line conductor 2 I 9. The other conductor 233 isconnected to the conductor 222.

Thus the synchronous clock motor is constantly connected to the voltenergizing circuit, through the limit switch.

The relay 225 controls a pair of contacts 234, 235, and the contact 235is connected by the conductor 236 to the contact 2 |1 of the operatingswitch. The contact 234 of the relay is connected by the conductor 231to the conductor ZIB.

The conductor 236 has a branch 239 extending to the terminal of themotor I0, and the conductor 222 has a branch 240 extending to theterminal of the motor IIJ. By tracing this circuit it will be noted thatthe motor I0 is controlled by the contacts 234, 235 of the relay 225.'I'he contact 2|1 of the operating switch 2|6 is connected to theconductor 236. The contact 2|8 of the operating switch 2 |6 is connectedby the conductor 24|a to the electromagnet |15, which forms a part ofthe control unit |60. The other terminal of the electromagnet |15 isconnected to the conductor 222.

Thus it will be seen that the operating switch 2|6, which closes on highbonnet temperature, is in series with the electromagnet |15 so thatwhenever this operating switch is closed or the bonnet reaches apredetermined temperature, the electromagnet |15 is energized. Theeffect of this energization is to draw the control plate |91 over towardthe magnet by means of armature |84 (Fig. 2) to the position of Fig. 2,and the reciprocating actuating member |64 will then strike the upwardlyextending flange 206 and move the housing |51 from the full lineposition of Fig. 6 to the dotted line position at the right. That is,the housing moves over to the minimum air feed and minimum coal feedposition, carrying with it the air feed and coal feed levers.

The stoker motor Ill is in the 110 volt A. C. circuit by reason of itsconnection through conductor 246 to conductor 222 to power lineconductor 2|0. On the other terminal the motor is connected to conductor239, conductor 236, relay contacts 234, 235, 231, and 2|9, limit switch2| 4, line conductor 2||. Thus the motor I0 is controlled by the limitswitch 2| 4 and by the relay 225.

The conductor 221 extends to one of the contacts 24| of a roomthermostat 242, the other contact arm being 243. Contact arm 243 isconnected to conductor 23|. Room thermostat 242 is thus connected inparallel with the time switch 228, and the room thermostat 242 alsocontrols the relay 225. The room thermostat 242 is so arranged that itopens the circuit on being heated to a predetermined point and closesthe circuit on being cooled to a predetermined point.

Thus the motorv may be operated either by the room thermostat 242 or thetime switch 228, which is actuated by synchronous electric clock 238.The synchronous clock and time switch act as a pilot circuit for turningon the coal feed and air feed periodically at intervals which aresufficiently short to insure the maintenance of a iire.

The pilot cannot, however, turn on the coal and air feed when the limitswitch is open because the synchronous clock 238 is in series with thelimit switch 2 I4, and the limit switch is open when the furnace isalready too hot and needs no pilot firing.

The operation of the control system and the mechanism is as follows:There are three general types of heating plants in which the presentcontrol system may be used. When the heating plant is a hot air furnace,the limit switch 2|4 and the operating switch 2 I6 would bethermostatically actuated switch members,.including any standard type ofthermostat.

These switches 2|4 and 2|6 would be disposed in the bonnet of thefurnace, and would be actuated when the bonnet reaches the propertemperatures.

When the heating plant comprises a steam or vapor installation, thelimit switch 2|4 Yand operating switch 2|6 may be actuated by pressureresponsive devices which correspond to the pressure in the boiler, andthese devices would have their pressure responsive bellows or a bulbconnected to the bellows located inside the boiler.

When the system is a hot water system, the switches 2|4 and 2|B would beactuated responsive to the temperature of the water in the system at theboiler. 'I'hey would comprise thermostatically-actuated switches, withthe thermostat located to be heated from the water of the boiler.

The system is illustrated with the coal feed on low feed in Fig. 1. Thecontrol switch 2| 2 should, of course, be closed in order to energizethe electrical system. Suppose, for example, the installation is beingused on a steam boiler. The operating switch 2|6 will be set to cut thecoal and air feeds from high to low when the steam pressure reaches, forexample, three pounds on an installation designed to operate from zeroto five pounds.

The contacts 2|1, 2|8 of thoperating switch Y toward the electromagnet|15 so that the oscillating lever |84 has' pulled the housing |51 towardthe right to the dotted line position' of Fig. 6, placing the device onlow coal feed and low air adjustment.

It happens that the low coal feed has been set at zero, which means thatno coal is being fed at all. If desired, the low coal feed may be madein any of the various adjustments indicated on the coal feed adjustment,and the zero coal feed would probably only be used in warm weather,while in colder weather the low coal feed might be raised to I, so as tomaintain a better fire all of the time except when the limit switch isopen.

Suppose, under these conditions, the room thermostat 242 shows a demandfor heat in that it is closed because it has cooled; and supposev thelimit switch 2 I4, which is set at ve pounds steam pressure, is closed,as it would be if the boiler had not reached a pressure exceeding thispredetermined maximum value.

The room thermostatswitch 242 closes at a predetermined temperature, andthen we say .it is demanding heat. Under these conditions the relay coil225 would be energized, and the con- -tacts 234, 235 closed, to energizethe motor and the electromagnet |15, if the operating switch 2| 6 isclosed. The operating switch 2 6, of course, closes on high bonnettemperature.

If the steam pressure is below three pounds, the operating switch 2|6will be open, and when the motor |0 is energized, causing the coal feedto commence, the reciprocating lever |64 will constantly oscillate backand forth. The electromagnet will be de-energized because the operatingswitch 2|6 is open, and the control plate |91 (Fig. 2) will take aposition farthest from the electromagnet |15.

The lever |64 will have its depending flange 1 |61 engage the upwardlyextending flange 205 and move the control housing |51 from the dottedline position of Fig. y6 to the full line position. In other words, thiswill move the coal feed stop |39 over to position 4, and theairadjustment lever |25 with its bent extension |4| to the right end of theair adjustment slot. The coal feed will be placed on high coal feed, andthe air adjustment will be opened to maximum opening. If, under the sameconditions, the steam pressure in the boiler has already reached threepounds and the room thermostat demands heat, the operating switch 2|6will be closed and the electromagnet |15 will be energized.

Then the control plate |91 will be at its minimum distancefr'om theelectromagnet |15, and the housing |51 will remain in the dotted lineposition of Fig. 6 because the plate |91 is not in position to have theflange 205 engaged by the oscillating lever |35. Instead, the lever |64-has its flange |61 engaging the arm 206.

Then the demand of heat by the room thermostat will merely energize themotor I through the relay 225, and coal will be fed at low feed toprovide an increased amount of steam or vapor" pressure until the vaporpressure reaches maximum, when the limit switch will open and stop themotor from feeding coal or air.

Sometimes after such a .cycle of operation as previously described,where the operating switch is open because the steamv pressure is belowthree pounds, the steam pressure will continue to rise to, for example,four pounds, and sometimes to five pounds. This is due to the extraamount of coal which was put into the furnace during the previous cycle,before the limit of three pounds pressure was reached.

This amount of pressure over-run will vary, depending upon the length oftime that the Stoker has been olf and depending upon how cold thefurnace is and how cold the temperature is, and how low the temperatureis in the house to be heated. For instance, if the stoker had been offall night, the plant would be cold, thus taking longer to build up threepounds. If it takes longer to build up three pounds pressure, the stokerwould operate a longer time on high, due to this condition; and it wouldnaturally build up a larger supply of coal in the furnace before thethree pound pressure was reached.

Thus it would follow that, with a greater amount of coal in the furnacewhen the st oker was out from high to Ilow feed, plus the coal which maybe continued to feed into the furnace on the low setting, the furnacemight reach the ve pound setting on the limit switch.

If this should happen, the limit switch 2I4 would' open and stop theStoker until the steam pressure dropped to, for example, four pounds,when the stoker would restart; and then it would naturally be operatingon the low coal feed and low air feed setting, because we have assumed acondition existing at the'time the stoker was cut from high to low feed.

Ordinarily during the day the limit switch setting will never be reachedbecause the stoker will be' cut from high to low feed with a smallenough iire or fuel bed to keep the steam pressure at approximatelythree to four pounds.

I have found that in most cases the stoker is invariably stopped by theroom thermostat being satisfied after theY stoker hasbeen operating onlow settings for a long 'enough period of time to have the fuel or rebed very low. Thus a saving of from eighteen to thirty-three andone-third percent in fuel is accomplished, and at the same time theroomtherrnostat is not overrun, asis :the P case with the standard-stokerf devicesoflthe 'priorart.

In the prior-art v devicesfthe f eeds must' be high 'enough to bring upthe temperature and-to maintain the load during vthe v`ctldest weather;'but thisV inevitably brings about a'y temperature over- -run at theroom thermostat withthe devicesof the prior art.

-As distinguished "from this, I-*have vvfound that *the present systemwillfmaintain the vroom temperature of my stokerlred 'system Aso uniformthat it does not'varyonelhalf degree F. during a twenty-four ihourperiod of operation, while the outside temperature "drops-fromf44degrees T. -`tol12 degrees' F. belowv zero.

Referring now to Fig. `1'6,=this is a modie'd 4wiring fdiagramywhich `isinlevery respect the same'as the diagram of`-Fig.1,1except thattheoperating switch circuitf includes `an outside-temperature control,which vis connected in yparallel 'with theoperatingswitch211,'2|8. Thisoutside switch is vindicated bythe `numeral 1250. vThis A V'outsideswitch `may "consist of 'a thermostatic "switch having contacts S251,252 in :series .with -the operating switch lT2 |16 land* velectromagnet115. The outside temperature 'control switch 'T250 opensrwhen itisfcooled V"and -is set 'at about 40 V'degrees It iis adapted to f makei the f control of 'l the A furnace orl boilerlbylthe'- operating-switchZ I 6 subject to the itemperature I outside the housefso that`loW coal feed and-- air ffeed Vadjustment are notused except when :itis quite warmronthe outside'f thebulding.

'Thelpurpose of fthe outsides'switch25ll'is :to re the stoker at fullrate '.vvhen'ithe temperature is belowfforty degrees Theswitch'=250:opens at "this'flowtemperature. Landi-:must .beAin:parallel` so that either i the' opening offthiszswitch or=v the: opie'ratingfswitchwill'v controlthe change 'ofthe feed 'ffrom low? to'high. A close'cif'circuit is required in i the circuit on rthe.1electromagnet |215 to put t the 'ifeed onlow.

'The outsidetemperaturecontrolf,switch 250..is:a "useful radjunet .z forcold weather, as .it tends :to lmake theapplicationg'f lowicoalfeedsubject to 'fthe :existence of :warm "..weather :outside of .theSfhouse.

One of the newresultsfaccomplished :byzthe "present system is thatwten'lperatnreroverruns are zeliminated :because :the f'green :eoal:force'd 1 in on `-the high"re isz--sbstantially-eall burned uprjustbefore Vthe Athermostatisfsatisled on'the :low frng"Suppose,:for-examp1e, .the'fstokerhasbeen cut to low! feed'andthersteammressure :drops one rpound, but 1 thetemperature:settingaoff the room "thermostat -.has not'rbeen-freached..:Thengthercon- .ztactsofthe operatingswitch 2i6'awill openand ftheelectromagnet "will ireleaser the control lplate 7191,.-an`d`. thecontrol unithousing willfbe-moved @rover :counterclockwiseztoetherfullflineposition of rfFig. L 6 to the: high4 fee'd:coalzandzarnadjustment,

where they will remain untilthe-threegpound; pres- -sure hasagain beenreached.

uit this .point :the Yoperating'.switch32H5 .will eagainfclose;l andoperate: thetze'lectromagnet j i 'l5 to 'fsett thecoalzandfainfeedmnlowllntil.the .pressure hasdroppedagain'to:aboutfone-pound.

:Thus the stokerriszordinarily' operated-between rythree:andzonefpoundrpressureratfalliztimesfexcept :thefcase :of thecold fboiler if at the-f1 start, in @which casefthe highnor :.veipound-limit setting wmightibereached.

v"When the',systemfis;installedrin'farhotsair furfmace, the .limitiswitch I4 fwould comprise. a ther-.fmostaticsswitch;,:having;asettingz0f.1iorizexmple.

:2g-seaman v350 1 degrees "The operatingrswitch 2 I.6 inthe plenumchamber would bera-thermostaticgswitch, having f afsetting of, ifor:example,'15Q :degrees F. This would mean that: ifthe:temperature.=exceeds -150 degrees F., the 4coal'and:airfeedz-Wouldxbe moved over to low adjustment. Iftheitem'peravrture decreased :below 150degre.es.F., Ythe coaliand airfeed adjustmentfwouldbe moved over toihigh 'feedadjustment ;I desire;Vit'to be z understood that 'the :temperaitures'whichiareused'aszexampiesiin this description `are merely-for the-purpose `ofrillustration. .and :the present device mayhearranged .topopferateratanyv temperatures suitable. for stokerred vheating plants.

,Thesadvantages of thepresent system as com- .pared withmypriorrapplicationare vthat 1only one 'motor is -`required, andtheelimination of -the 'control-motor utilizedv inmy prior inventiongreatly ldecreases the ,cost of the installation. vFewerfoperatingswitches and circuitsrare required, and the: systemhasbeenesimplied. over, myE por invention.

' The vadvantages of 4the i system whichy are :also

`present in my pror device may ithenbesumf marized as follows 1.Temperature overruns in v,theroom .to be heated aresubstantially;eliminated,.aandtthe :tem-

perature is maintained within One-haIfdegreeOf the room-thermostatsetting.

2. There is a substantialsaving of fromeighteen .to:thirtythreeandone-third percentof fuelbecause `.the green fuel .that ,is forced 4in.onl high :feed is fully burned up after-Ward. on vlow feed.

3. Less electric current v.is consumed, as the coal :feed 'and iair`feedrrecluire less .power .when `they..areioperated at low feedasin.t,he ,devices .of the prior art.

4. Coke trees or large shafts of cokeare Aeliminated,;due toLtifiecuttingoi the .coalfeed from high to. low, during .which lowf.eed.they areconsinned.

.5. The, hard clinkerswhichusually.form inthe vdevices of the prior artover the burner andarollnd .the retortare broken up ,and moved Aover ztothe side or top of the, fire. because .suchclnkers as are formedzonhighieedarebroken ,up by thecon- 4tinuance of the feed ,of fuelon low,,and.ther,e is .no1 opportunityfor the., elinkersto` cool .and settlerdownover the burner, .as they doin theI devices of the prior vart,.w,here coal is fedat highfeed and then completely Cutoff.

6. `The Stokerv retort will last.indefinitely,y orits 11'fe..will, inany event, begreatly increased .be-

cause when the burner is stoppedthereisno large hot mass directly over.andaround the retort. Ehe, coal red intheretort yand above itA has beenbrokenup intosmallipieces and` cooled When operating on loWrfeed, andthe continuance of the flow, of ther coolingair has alsoy served tokeepthe retort, cool.

V'7. ,The presentcontrol unit permits the independent setting of`highair feed andflow air feed, ,.andhighcoalhfeed, and low,coal'fe,ed,so that the systemis .flexible and adaptable tosalhkinds of aseaesoVclaim as new and desi-re to secure. by Letters Patent of the UnitedStates, is:

1. In a controlling unit for coal stokers, the combination of anelectricdriving motor with a power takeoff fromsaid electric motor and a conatrolling unit for controlling coal feed adjustment, said controllingunit having a movablel mounted electric control magnet adapted toYoscillate between a maximum and a minimumcoal feed adjustment, a memberhaving a pair of thrust surfaces controlled by said magnet, and meansactua-ted by said power takeoff and selec tively engageable with one orthe other thrust surfaces of said member for moving said control magnetto either a maximum or minimum coalI feed adjustment, depending upon theposition of said magnet control member, and coal feed regulating meanscontrolled by the maximum or minimum coal feed adjustment of saidmagnet.

2. In a controlling unit for coal stokers, the combination of anelectric driving motor with a power takeoff from said electric motor anda` rmagnet control member,l coal feed regulating means controlled by themaximum or minimum coal feed adjustment of said magnet, a frictionclutch interposed between said coal feed regulating means and saidmagnet, and adjustable stop means to be engaged by said coal feedregulating means whereby one of the limits of motion of said coal feedregulating means may be determined by said stop means, said clutchpermitting the full oscillating movement of said magnet.

3. In a controlling unit for coal stokers, the combination of anelectric driving motor with a power takeoff from said electric motor anda controlling unit forl controlling coal feed adjustment, saidcontrolling unit having a movably mounted electric control magnetadapted to oscillate between a maximum and a minimum coal feedadjustment, a member having a pair of thrust surfaces controlled by saidmagnet, means actuated by said power takeoff and selectively engageablewith one or the other thrust surfaces of said member for moving saidcontrol magnet to either a maximum or minimum coal feed adjustment,depending upon the position of said magnet control member, and air feedregulating means controlled by the movement of said magnet.

4. In a Stoker controlling system, the combination of a coal feedingmember, with a coal feed motor, selective speed driving means interposedbetween said coal feeding member and the drive shaft of said motor, acoal feed adjustment member adapted to change the adjustment of saidmeans to provide coal feeds of predetermined amount, a coal feedcontrolling unit having a pair of adjustable stops, an operating switchsubject to conditions produced at a heater, and an electromagnetcontrolled by said operating switch, an armature for said electromagnet,said armature having an engaging part, an oscillating member driven bysaid motor, said part engaging one side of said oscillating member whenthe electromagnet. is energized and'. engaging the. other side of saidoscillating member when the; electromagnet is de-energizeds saidelectromagnet; and armature being movably mounted for mover mentby saidoscillating member, and drive means between said electromagnet and saidcoal feed adjustment member for moving saidcoal feed adjustment memberfrom one to the other of said stops to provide high or low coal. feed.

5. In a Stoker controlling system, the combination of a coal feed with amotor and variable speed means for driving said coal. feed, a combustionair blower, and an air valve for control-A ling the amount of airsupplied by said blower, said blower being driven by said motor, a. coaland air feed control unit having two adjustable stops for coal feed andtwo adjustable stops, for air feed, and a feed adjustment unit adaptedto.. be driven by said motor to either oftwo positions of high or lowfeed determined by the adjust.- ment of said coal and air feed stops.

6. In a controlling unit for coal stokers, the combination of anelectric. driving motor withV a power takeoff from` said electric motorand a` con. trolling unit for controlling coal feed adjustment, saidcontrolling unit having a movably mounted electric control magnetadapted to oscill-ate between a maximum and a minimum coalA feed ad-Ajustment, a member having a pair of thrust surfaces controlled by saidmagnet, means actuated by said power takeoffV and selectively engageablewith one or the other thrust surfaces of said member for moving saidcontrol magnet to either a maximum or minimum coal feed adjustment,depending upon the position of said magnet control member, and air feedregulating means controlled by the movement of said magnet, a, frictionclutch interposed between said feed regulating means and said magnet,and an adjustable stop member located to be engaged by said air feedregulating means whereby one of the limits of the range of air feed maybe determined by the location of said stop member, said clutchpermitting said magnet to oscillate through its full range of movement.

'7. In a controlling system for solid fuel burn-- ers, the combinationof an electric drive motor with a speed reduction gear system having arnechanical power take-off on said gear system, coal feed and air feedmeans adapted to be driven said motor, and having means for changing therate of coal feed and the rate of air feed, said power takeoff beingoperatively connected to the coal feed and air feed adjusting means tomove the coal feed or air feed to high or low positions,electromagnetically actuated connecting means between said powertake-off and the coal feed and air feed means, and thermostatic meanscontrolled responsive to the production of heat for controlling theenergization of said electromagnetically actuated connecting means andthe pc- 'sition of its connecting means in moving the coal feed or airfeed to high or low position,

8. In a controlling system for solid fuel burners, the combination of anelectric drive motor with a speed reduction gear system having amechanical power take-off on said gear system. coal feed and air feedmeans adapted to be driven by said motor, and having means for changingthe rate of coal feed and the rate of air feed. said power take-offbeing operatively connected tothe coal feed and air feed adjustingmeansto move the coal feed or air feed to high or low positions,electromagnetically actuated connecting means between said powertake-.off and the coal feed and airlfeed adjustingmeans, andthermostaticmeans controlled vresponsive tothe production ofheat for controlling theenergization of said electromagnetically actuated connecting means inmoving the coal feed or air feed to high or low position, and clutchmeans interposed between said coal feed and said power1 take-off, and anadjustable stop determiningone of the limits of motion of the coal feedadjustment whereby the coal feed adjustment may be predetermined bylocating said adjustable stop at one of its limits without affectingtheoperation of the power take-off, the clutch permitting slipping afterthe coal feed adjustment has engaged said stop.

9. In .an air feed adjustment controlling unit for furnaces, thecombination of a support, an electromagnet movably mounted on saidsupport, ai'rfeed4 controlling means actuated by movement of saidelectromagnet for regulating the amount of air feed to the furnace, adriving motor, a power take-off from said driving motor having anoscillating member, an armature movably mounted with respect to saidelectromagnet, a part carried by said'armature and having offsetshoulders facing in opposite directions, to be'engaged by saidoscillating member to move the armature and electromagnet in onedirecti'on to regulate the air feed when the electromagnet is energizedand to move the electromagnet and armature in the other direction whenthe electromagnet is ole-energized.

'10. In a fuel feed adjustment controlling unit for furnaces, thecombination of a support, an electromagnet movable mounted on saidsupport, a fuel feed controlling means actuated by the movement of saidelectromagnet for regulating the'amount of 'fuel feed to the furnace, adriving motor, a power take-off from said driving motor having anoscillating member, an armature movably mounted with respect to saidelectromagnet, a part carried by said armature and havinga pair ofoffset shoulders alternately engageable with the oscillating member uponenergization or deenergization of the electromagnet, whereby the fuelfeed controlling means may be moved in one direction or the other,depending upon the energization of the magnet.

11. In an air feed adjustment controlling unit for coal stokers, thecombination of a driving motor with an air pressure-creating unit,throttling means for controlling the flow of air through said latterunit, an oscillating member driven by said driving motor, a controllingmember for controlling the position of said throttling means, saidcontrolling member comprising an air feed adjustment lever, a selectivelever adapted to be engaged in one position by the oscillating member tobe moved in one direction and in another position to be moved in theopposite direction for actuating the air feed adjustment lever, slippingclutch means operatively connected to said selective means and said airfeed adjustment lever, and an adjustable stop for said air feedadjustment lever for determining one of its limits of motion'whereby themovement of the air feed adjustment lever to one of its positions may becontrolled by said stop, the clutch permitting slipping and permittingthe oscillating member to continue its full range of movement after theair feed adjustment lever has engaged its said stop.

A 12'. In a coal feed system for stokers, the combination of a supportwith a driving motor, coal feeding means for said stoker and operativeconnections between said driving motor and said coal feeding means,whereby said; coall feeding means may be driven at higher orV lowerrates of feed, a coal feed adjustment lever actuated by said operativeconnections and adapted to regulate the rate of coal feeding by movementof said coal feed adjustment lever, an oscillating member, a powertake-olf from said driving motor for driving said oscillating memberthrough a constant amplitude, a selective member mounted for oscillatingmovement and adapted to drive said coal feeding adjustment lever to highor low coal feed position, a slipping clutch operatively connected tosaid selective member and said coal feed adjustment lever, saidselective member being adapted to be positioned to engage one side orthe other of said oscillating member whereby said selective member isdriven to high or low coal feed adjustment position through a constantamplitude While the coal feed adjustment levei` may move only apredetermined amount, the clutch slipping after the coal feed adjustmentlever reaches the limit of its amplitude.

13. In a coal feed system for stokers, the combination of a support witha driving motor, coal feeding means for said stoker and operative,connections between said driving motor and said coal feeding means,whereby'said coal feeding means may be driven at higher or lower ratesof feed, a coal feed adjustment lever connected to said operative meansand adapted to regulate the rate of coal feeding by movement of saidcoal feed adjustment lever, an oscillating member, a power take-off fromsaid driving motor for driving said oscillating member through aconstant.-

amplitude, a selective member mounted for oscillating movement andadapted to drive said coal feeding adjustment lever to high or low coalfeed position, a slipping clutch operatively connected to said selectivemember and said coal feed adjustment lever, said selective member beingadaptedrto be positioned to engage one side or the other of saidoscillating member whereby said selective member is driven to high orlow coal feed adjustment position through a constant amplitude -whilethe coal feed adjustment lever may move only a predetermined amount, theclutch lslipping after the coal feed adjustment lever reaches the limitof its amplitude, and an adjustable stop member for engaging said coalfeed adjustment lever and determining one of its limits of motion,whereby the amount of coal feed may be adjusted by merely adjusting saidstop member.

14. In a stoker controlling system, the combination of a coal feedingmember with a coal feed motor, selective speed driving means interposedbetween said coal feeding member and the drive shaft of said motor, acoal feed adjustment member adapted to change the adjustment of saidmeans to provide coal feeds of predetermined amount, a coal feedcontrolling unit having a pair of adjustable stops, an operating switcnsubject to conditions produced at a heater, and an electromagnetcontrolled by said operating switch, said drive means comprising afriction clutch operatively connected to said movable electromagnet andsaid coal feed adjustment member, whereby the adjustment of the stopsmay be made independent of the amount of' movement of the electromagnet,for moving said coal feed adjustment member from one to the other ofsaid stops to provide high or low coal feed.'Y l

WILLIAM W. HALLINAN

